package com.cnh.framework.util;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.net.JarURLConnection;
import java.net.URL;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Set;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

/**
 * @author cnh
 * @create 2019-02-14 11:45
 * 说明：
 */
public class ClassUtil {
    private static final Logger LOGGER = LoggerFactory.getLogger(ClassUtil.class);

    /**
     * 获取类加载器
     */
    public static ClassLoader getClassLoader() {
        return Thread.currentThread().getContextClassLoader();
    }

    /**
     * 加载类
     */
    public static Class<?> loadClass(String className, boolean isInitialized) {
        Class<?> aClass;
        try {
            aClass = Class.forName(className, isInitialized, getClassLoader());
        } catch (ClassNotFoundException e) {
            LOGGER.error("load class fail", e);
            throw  new RuntimeException(e);
        }
        return aClass;
    }


    /**
     * 加载类
     */
    public static Class<?> loadClass(String className) {
        return loadClass(className, true);
    }


    public static Set<Class<?>> getClassSet(String packageName){
        Set<Class<?>> classSet = new HashSet<>();
        try {
            Enumeration<URL> urls = getClassLoader().getResources(packageName.replace(".", "/"));

            while (urls.hasMoreElements()){
                URL url = urls.nextElement();
                if(url != null){
                    String protocol = url.getProtocol();
                    if(protocol.equals("file")){
                        String packagePath = url.getPath().replaceAll("%20", "");
                        addClass(classSet, packagePath, packageName);
                    } else if (protocol.equals("jar")){
                        JarURLConnection jarURLConnection = (JarURLConnection) url.openConnection();

                        if (jarURLConnection!=null){
                            JarFile jarFile = jarURLConnection.getJarFile();
                            if (jarFile != null) {

                                Enumeration<JarEntry> jarEntries = jarFile.entries();

                                while (jarEntries.hasMoreElements()){
                                    JarEntry jarEntry = jarEntries.nextElement();
                                    String jarEntryName = jarEntry.getName();
                                    if(jarEntryName.endsWith(".class")){
                                        String className = jarEntryName.substring(0, jarEntryName.lastIndexOf(".")).replaceAll("/", ".");
                                        doAddClass(classSet, className);
                                    }
                                }

                            }
                        }
                    }
                }
            }
        } catch (IOException e) {
            LOGGER.error("get class set failure", e);
            throw new RuntimeException(e);
        }

        return classSet;

    }

    private static void addClass(Set<Class<?>> classSet, String packagePath, String packageName) {
        File[] files = new File(packagePath).listFiles(new FileFilter() {
            @Override
            public boolean accept(File file) {
                return (file.isFile() && file.getName().endsWith(".class")) || file.isDirectory();
            }
        });

        for (File file : files){

            String filename = file.getName();
            if (file.isFile()){

                String className = filename.substring(0, filename.lastIndexOf("."));
                if(StrUtil.isNotEmpty(packageName)){
                    className = packageName + "." + className;
                }
                doAddClass(classSet, className);

            } else {
                String subPackagePath = filename;
                if(StrUtil.isNotEmpty(packagePath)){
                    subPackagePath = packagePath + "/" + subPackagePath;
                }
                String subPackageName = filename;
                if(StrUtil.isNotEmpty(packageName)){
                    subPackageName = packageName + "." + subPackageName;
                }

                addClass(classSet, subPackagePath, subPackageName);
            }


        }
    }

    private static void doAddClass(Set<Class<?>> classSet, String className){
        Class<?> cls = loadClass(className, false);
        classSet.add(cls);
    }

}
